Needle assembly for use with a biopsy device

ABSTRACT

A needle assembly comprises an outer cannula and an inner cannula. The outer cannula and the inner cannula have complementary tissue receiving apertures. A tissue piercing tip is secured relative to one or both of the inner cannula or the outer cannula. A cutter is slidably disposed in the inner cannula. The cutter is configured to sever tissue protruding through the transverse apertures. A hub releasably secures at least part of the needle assembly relative to the body of a biopsy device.

PRIORITY

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 12/437,961, entitled “Method of Manufacturing aNeedle Assembly for Use with a Biopsy Device,” filed May 8, 2009, thedisclosure of which is incorporated by reference herein, and which is adivisional of U.S. Non-Provisional patent application Ser. No.11/027,120, entitled “Method of Manufacturing a Needle Assembly for Usewith a Biopsy Device,” filed Dec. 30, 2004, the disclosure of which isincorporated by reference herein.

FIELD OF THE INVENTION

The present invention is related generally to biopsy devices and, moreparticularly, to an improved process of manufacturing a needle assemblyfor use with a biopsy device for acquiring a tissue sample.

BACKGROUND OF THE INVENTION

The diagnosis and treatment of patients with cancerous tumors,pre-malignant conditions, and other disorders has long been an area ofintense investigation. Non-invasive methods for examining tissue includepalpation, thermography, PET, SPECT, Nuclear imaging, X-ray, MRI, CT,and ultrasound imaging. When the physician suspects that tissue maycontain cancerous cells, a biopsy may be done either in an openprocedure or in a percutaneous procedure. For an open procedure, ascalpel is used by the surgeon to create a large incision in the tissuein order to provide direct viewing and access to the tissue mass ofinterest. Removal of the entire mass (excisional biopsy) or a part ofthe mass (incisional biopsy) is performed. For a percutaneous biopsy, aneedle-like instrument is inserted through a very small incision toaccess the tissue mass of interest and to obtain a tissue sample forlater examination and analysis.

The advantages of the percutaneous method as compared to the open methodare significant: less recovery time for the patient, less pain, lesssurgical time, lower cost, less risk of injury to adjacent bodilytissues such as nerves, and less disfigurement of the patient's anatomy.

Generally there are two ways to percutaneously obtain a portion oftissue from within the body: aspiration and core sampling. Aspiration ofthe tissue through a fine needle requires the tissue to be fragmentedinto pieces small enough to be withdrawn in a fluid medium. This methodis less intrusive than other known sampling techniques, but one may onlyexamine cells in the liquid (cytology) and not the cells and thestructure (pathology). In core sampling, a core or fragment of tissue isobtained for histologic examination and/or genetic tests, which may bedone via a frozen or paraffin section. The type of biopsy used dependsmainly on various factors present in the patient, and no singleprocedure is ideal for all cases. However, core biopsies seem to be morewidely used by physicians.

The following patent documents are incorporated herein by reference forthe purpose of illustrating biopsy devices and methods: U.S. Pat. No.5,526,822 issued Jun. 18, 1996; U.S. Pat. No. 5,895,401 issued Apr. 20,1999; U.S. Pat. No. 6,086,544 issued Jul. 11, 2000; U.S. Pat. No.6,620,111 issued Sep. 16, 2003; U.S. Pat. No. 6,626,849 issued Sep. 30,2003; U.S. Pat. No. 6,638,235 issued Oct. 28, 2003; US PatentApplication 2003/0109803 published Jun. 12, 2003; US Patent Application2003/0199753 published Oct. 23, 2003; US Patent Application 2003/0199754published Oct. 23, 2003; US Patent Application 2003/0199785 publishedOct. 23, 2003; and U.S. Ser. No. 08/825,899 filed on Apr. 2, 1997.

It is known in the art to use a double lumen biopsy needle incorporatingvacuum suction to obtain a tissue sample. With devices of this type, theneedle is inserted into a small incision in a patient and is advancedthrough tissue until the needle is adjacent the tissue of interest. Atthat point, a vacuum source may be activated, providing suction insideone of the two lumens. The suction is communicated to the second lumenvia a passage between the two lumens. The second lumen may contain anaperture through which suspicious tissue may be drawn when the vacuumsource is activated. Once tissue is drawn into the aperture, the surgeonmay advance a cutter through the second lumen in order to excise asample from the tissue of interest.

While biopsy needles of the type described above are useful in obtainingtissue samples, the processes known in the art for manufacturing theseneedles are often expensive and labor-intensive due to the number ofcomponents and steps involved. For instance, certain biopsy needlesprovide a double lumen structure formed of two separate rigidstructures, thus requiring a reliable method of attaching the twostructures, such as a weld or adhesive, along the entire length of thelumens. Similarly, many biopsy needles include a sharpened feature onthe leading end of the needle that cuts through tissue as the needle isadvanced into the body. These sharpened tips often have small componentsand/or features that require significant time and expense to make andattach to the needle. Further, biopsy needles often include a mountingcomponent that allows the needle to be attached to a handle or otherplatform. Often, these mounting components are manufactured separatelyfrom the body of the needle, and must be joined together afterformation, such as by gluing, a process that is heavily reliant on theskill and concentration of a human worker. Even if a more reliablemethod of attaching the mounting component to the needle is used, suchas induction heating or heat staking, such methods still involve theadded expense necessitated by the extra assembly equipment as well asthe steps of manufacturing the mounting component and attaching it tothe needle.

Accordingly, while double lumen biopsy needles are known in the art,there exists a significant need for a process of manufacturing a biopsyneedle that reduces the number of components that must be separatelymanufactured, as well as the time and labor that must be expended inmanufacturing and assembling the components of the biopsy needle, whilestill maintaining the necessary strength and rigidity for safe andsatisfactory performance during surgery.

SUMMARY OF THE INVENTION

The process of the current invention overcomes the above-noted and otherdeficiencies of the prior art by providing a process for manufacturing abiopsy needle device that reduces the number of components that must beseparately manufactured and assembled, thereby reducing the cost ofmanufacturing the biopsy needle device while maintaining the necessarybiomechanical properties.

In one aspect consistent with the present invention, a process ofmanufacturing a biopsy needle may comprise the steps of forming anaperture for receiving tissue to be sampled in an exterior surface of anelongated tube that has a proximal and distal portion, wherein theelongated tube may be configured to receive a cutter; forming a hole inthe exterior surface of the elongated tube; and applying a coating ofmaterial over the elongated tube to form a lumen for receiving vacuum onthe exterior surface of the elongated tube, wherein the hole in theexterior surface of the elongated tube may be adapted to providecommunication between an interior of the elongated tube and an interiorof the lumen. This process advantageously allows the vacuum lumen to beformed over the elongated tube without requiring separate manufacturingand assembly steps, thus reducing assembly costs.

In another version, the process of manufacturing the biopsy needledevice may comprise the steps of forming an aperture for receivingtissue to be sampled in an exterior surface of an elongated tube,wherein the elongated tube may be adapted to receive a cutter and mayfurther comprise a proximal portion and a distal portion; forming a holein the exterior surface of the elongated tube; and placing the elongatedtube in a mold and injecting the mold with a material, wherein the moldmay be configured such that the material forms a lumen for receivingvacuum on the exterior surface of the elongated tube, and whereinfurther the hole in the exterior surface of the elongated tube may beadapted to provide communication between an interior of the elongatedtube and the interior of the lumen. This version advantageously providesfor the formation of a vacuum lumen on an elongated tube by overmoldinga coating of material onto the elongated tube, avoiding the need toseparately manufacture the vacuum lumen and then attach it to theelongated tube. Further, this process may provide for a strongerattachment between the vacuum lumen and the elongated tube than somepreviously known methods of attachment of the two components.

In another aspect, the process of manufacturing a biopsy needle devicemay comprise the steps of placing a cutter tube, which may comprise aport adapted to receive a tissue sample and may further comprise acutter lumen adapted to receive a cutter, in a mold; injecting amaterial in a liquid state into the mold; cooling the material in orderto convert it to a solid state; wherein the mold may be configured tocause the material to form a lumen for receiving vacuum on an exteriorsurface of the cutter tube, and wherein further the vacuum lumen is incommunication with the cutter lumen.

The present invention also extends to a biopsy instrument manufacturedaccording to a process that may comprise the steps of forming anaperture for receiving tissue to be sampled in an exterior surface of anelongated tube for receiving a cutter, wherein the elongated tube mayhave a proximal portion and a distal portion; forming a hole in theexterior surface of the elongated tube; and applying a coating ofmaterial over the elongated tube to form a lumen for receiving vacuum onthe exterior surface of the elongated tube, and wherein the hole in theexterior surface of the elongated tube may be adapted to providecommunication between an interior of the elongated tube and an interiorof the lumen.

These and other objects and advantages of the process of the presentinvention shall be made apparent from the accompanying drawings and thedescription thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features and steps of the invention are set forth withparticularity in the appended claims. The invention itself, however,both as to organization and methods of operation, together with furtherobjects and advantages thereof, may best be understood by reference tothe following description, taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is an isometric view of a hand-held vacuum-assisted biopsy deviceincluding a needle assembly manufactured according to one version of theprocess.

FIG. 2 is a side view of a needle assembly manufactured according to oneversion of the process.

FIG. 3 is a top view of a needle assembly manufactured according to oneversion of the process.

FIG. 4 is a side view of a distal tissue-piercing tip manufacturedaccording to one version of the process.

FIG. 5 is an isometric view of a distal tissue-piercing tip manufacturedaccording to one version of the process.

FIG. 6 is a section view of a cutter lumen and cutter stop manufacturedaccording to one version of the process.

FIG. 7 is a section view of a cutter stop manufactured according to oneversion of the process.

FIG. 8 is a partial view of a cutter lumen and axial slide according toone version of the process.

FIG. 9 is an isometric view of a right half of a needle assembly moldwith slides in place for use in injection molding according to oneversion of the process.

FIG. 10 is a partial frontal cross-sectional view of a needle assemblymanufactured according to one version of the process.

FIG. 11 is a partial sagittal cross-sectional view of a needle assemblymanufactured according to one version of the process.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a hand-held vacuum-assisted biopsy device 10 comprising ahandle 20 detachably connected to a needle assembly 30 having a proximalportion 32 and a distal portion 34 manufactured according to a versionof the process of the current invention. Together, they constitute alightweight, ergonomically-shaped, hand-manipulated biopsy device 10. Inone aspect, needle assembly 30 may be part of a disposable probe thatmay mount on handle 20. In one aspect, hand-held biopsy device 10 may beused in conjunction with an ultrasound to guide needle assembly 30.Since handle 20 may be manipulated by the operator's hand, the operatormay steer needle assembly 30 with great freedom towards the tissue massof interest. The surgeon has tactile feedback while doing so and maytherefore ascertain to a significant degree the density and hardness ofthe tissue being encountered. In addition, handle 20 may be heldapproximately parallel to the chest wall of a patient for obtainingtissue portions closer to the chest wall than may be obtained whenneedle assembly 30 is attached to another type of device. Alternatively,needle assembly 30 may be attached to an electromechanical arm, aplatform, a table or other suitable support. Such alternative mountingsmay be used in conjunction with applications in which the needleassembly is guided by stereotactic (x-ray) or MRI modalities.

As controls for obtaining a tissue sample, handle 20 may include aforward button 36 which may be used to move a cutter 38 distally througha cutter lumen 40 to sever a sample of suspicious tissue collected in atissue-receiving port 42. Handle 20 may further include a reverse button44 which may be used to move cutter 38 proximally through cutter lumen40, thereby moving the tissue sample in port 42 to a tissue collectionsurface 46. A vacuum button 48 on handle 20 may be used to open or closea first vacuum line 50 for communicating suction to a vacuum lumen 52 soas to cause tissue to become disposed within port 42 and a second vacuumline 54 for communicating axial suction to cutter 38 to aid inwithdrawal of a severed tissue sample.

Referring now to FIGS. 2 and 3, a needle assembly 30 made by one versionof the process of the current invention for use with a biopsy device 10is illustrated. Cutter lumen 40 may comprise a proximal portion 56 and adistal portion 58. Cutter lumen 40 forms a smooth, uninterrupted passagefor receiving cutter 38 (not shown in FIGS. 2-3) such that it may beadvanced through the proximal portion 56 of cutter lumen 40 to thedistal portion 58. Tissue-receiving port 42 may be formed in an exteriorsurface 60 of cutter lumen 40. Port 42 may be located on the distalportion 58 of cutter lumen 40. Cutter lumen 40 may also comprise an openproximal end 62 and an open distal end 64.

Vacuum lumen 52 may comprise a proximal portion 66 and a distal portion68. In one version, cutter lumen 40 may be oriented above vacuum lumen52. A vacuum source (not pictured) may be attached to vacuum lumen 52,possibly at proximal portion 66 thereof, via first vacuum line 50.

The needle assembly 30 may also include one or more passages, alsocalled interlumen vacuum holes 70, between cutter lumen 40 and vacuumlumen 52. When the vacuum source is activated, thereby providing suctionin vacuum lumen 52, interlumen vacuum holes 70 allow that suction to becommunicated into cutter lumen 40. As best illustrated in FIGS. 3 and11, the interlumen vacuum holes 70 may be located between cutter lumen40 and vacuum lumen 52 opposite the tissue-receiving port 42. Asillustrated in FIG. 6, a cutter stop 72 may also be located in cutterlumen 40 distally of tissue-receiving port 42. A face 74 of cutter stop72 may provide a cutting surface for severing a tissue sample. Face 74of cutter stop 72 may be designed to match the leading profile of cutter38 (FIGS. 6 and 7). Depending on the means used to advance cutter 38,cutter stop 72 may also provide tactile feedback to a surgeon oncecutter 38 comes into contact with cutter stop 72 after a sample has beensevered. However, if, as known in the art, a computer software programis used to control advancement of cutter 38, the surgeon will not beprovided with tactile feedback by contact between cutter 38 and cutterstop 72.

As illustrated in FIG. 2, a hub 76 having a proximal portion 78 and adistal portion 80 may be located on proximal portion 32 of needleassembly 30. Hub 76 assists in mounting needle assembly 30 to handle 20or other any other suitable support. Hub 76 may detachably mount onhandle 20 in order to allow disposable needle assembly 30 to be removedfrom the multiple-use handle 20 after surgery. Hub 76 may also include aflange 82 on its distal portion 80. Flange 82 may snap into a rib orsimilar retaining element (not shown) of handle 20 or another suitablesupport. Hub 76 may also include a vacuum manifold 84 that provides aconnection between the vacuum source and vacuum lumen 52. Hub 76 mayalso allow second vacuum line 54 to connect with cutter 38 so that axialsuction may be communicated to cutter 38.

In one aspect consistent with the process of the current invention, adistal tissue-piercing tip 86 having a proximal portion 88 and a distalportion 90 may be disposed on distal portion 34 of needle assembly 30.As best pictured in FIGS. 4 and 5, distal portion 90 of distaltissue-piercing tip 86 may include a cutting edge 92 of sufficientsharpness to cut through human tissue and thereby aid in moving needleassembly 30 adjacent to the tissue of interest. The junction of piercingtip 86 and cutter lumen 40 may include a tapered profile 94 therebetweenthat further assists needle assembly 30 in moving smoothly through apatient's tissue.

Piercing tip 86, particularly the distal portion 90, may comprise asubstantially flat blade formed of any suitable material. Piercing tip86 may also include tabs 96, 98 (FIGS. 4, 5, 11) on proximal portion 88thereof to aid in the attachment of piercing tip 86 to cutter lumen 40.Tab 96 may be located above tab 98. In one version, tab 98 extendsfurther toward proximal end 62 of cutter lumen 40 than does tab 96 forreasons addressed below. Piercing tip 86 may also include an opening100, to aid in formation of tapered profile 94, which is also discussedin more detail below.

In operation, needle assembly 30 may be inserted into a small incisionin the body. When utilized, tissue-piercing tip 86 helps needle assembly30 penetrate through tissue until distal portion 34 of needle assembly30 is located adjacent the tissue of interest. Piercing tip 86, alongwith tapered profile 94, may help to minimize tissue drag experiencedduring insertion and extraction of needle assembly 30. Once needleassembly 30 is properly positioned relative to the tissue of interest,vacuum suction may be applied to vacuum lumen 52 via first vacuum line50.

Suction may be communicated from vacuum lumen 52 to cutter lumen 40 viathe interlumen vacuum holes 70. The suction inside cutter lumen 40actively pulls suspicious tissue into tissue-receiving port 42. Once thesuspicious tissue has been drawn into cutter lumen 40 through port 42,the surgeon may advance cutter 38 in the distal direction until a sampleis severed from the suspicious tissue. Cutter stop 72 may be located incutter lumen 40 distally of tissue-receiving port 42 to provide acutting surface to aid cutter 38 in severing a sample of suspicioustissue. Once the sample has been severed, cutter 38 may contact cutterstop 72. As mentioned above, depending on the means used to advancecutter 38 through cutter lumen 40, contact between cutter 38 and cutterstop 72 may provide tactile feedback to the surgeon, indicating that asample has been obtained and that cutter 38 may be withdrawn towardproximal end 62 of cutter lumen 40. Once cutter 38 contacts cutter stop72, needle assembly 30 may be repositioned in the patient's body (e.g.,rotated, longitudinally translated) in order to obtain another sample.

As mentioned above, cutter 38 may be attached to second vacuum line 54,thereby providing cutter 38 with axial suction. After a sample has beenobtained, and before a second sample is drawn into port 42, axialsuction, if utilized, may assist cutter 38 in pulling the sample throughcutter lumen 40 as cutter 38 is withdrawn. Once cutter 38 has beenwithdrawn from cutter lumen 40, the sample may be cleared from cutter 38onto the tissue collection surface 46 located on handle 20 or platform.At that point, another sample may be obtained by applying vacuum to drawa sample into port 42 and advancing cutter 38 to sever the sample. Thisprocedure may be repeated until the desired number of samples has beenacquired.

In one aspect consistent with the process of the current invention,cutter lumen 40 may comprise a preformed tube open at each end and cutto the desired length of needle assembly 30. The preformed tube may beadvantageously straight and round for receiving cutter 38. The materialof the preformed tube may be rigid to allow insertion of needle assembly30 through tissue with minimal deflection. In one version, cutter lumen40 may be made of metal. More particularly, cutter lumen 40 may be madeof stainless steel. Cutter lumen 40 may also be made from other suitablematerials, including but not limited to titanium, titanium alloy,aluminum, or aluminum alloy. Alternatively, cutter lumen 40 may be madefrom nonmetallic materials having structural characteristics sufficientto allow a coating of material to be applied over cutter lumen 40 andhaving the strength and rigidity characteristics sufficient to withstandthe force experienced by cutter lumen 40 when it is pressed throughhuman tissue.

Tissue-receiving port 42 and interlumen vacuum holes 70 may be cut intothe preformed tube comprising cutter lumen 40. As shown in FIG. 3, thedistal and proximal edges of port 42 may be cut on an angle relative tothe longitudinal edges of port 42. The angling of these edges canproduce a scissoring effect as needle assembly 30 is pushed throughtissue, aiding in positioning the device 10. In addition, a pair ofnotches 101, 102 (FIG. 8) may be cut into distal end 64 of the preformedtube comprising cutter lumen 40 to provide points of attachment forpiercing tip 86.

Piercing tip 86 may be formed of a material providing sufficientstrength and rigidity to allow it to move through tissue with minimaldeflection. In one version, tip 86, including the above-describedfeatures included thereon, may be stamped from metal sheet stock. Moreparticularly, the metal may be 440A stainless steel. However, othersuitable materials may be used, including but not limited to titanium,titanium alloy, aluminum, or aluminum alloy. Non-metallic materials,such as MRI compatible resins, including but not limited to Ultem andVectra, may be used to form tip 86 Likewise, tip 86 may also be formedfrom ceramics or glass. By stamping piercing tip 86 out of metal sheetstock, cutting edge 92 may be sharpened prior to attachment of tip 86 tocutter lumen 40. Cutting edge 92 may be sharpened after formation of tip86 by grinding perpendicular to cutting edge 92, which is sometimesthought to be advantageous in producing a sharp cutting surface.Alternatively, cutting edge 92 may be sharpened by any other suitablemethod known in the art.

Piercing tip 86 may be attached to cutter lumen 40. In one version,piercing tip 86 may be welded to cutter lumen 40. More particularly,piercing tip 86 may be laser welded to cutter lumen 40. In one version,piercing tip 86 may be welded to cutter lumen 40 at two preformedlocations. Tabs 96, 98 of piercing tip 86 may each be welded inside thenotches 101, 102 of cutter lumen 40. Alternatively, piercing tip 86 maybe attached to cutter lumen 40 through any suitable method known in theart that provides satisfactory strength of attachment between tip 86 andcutter lumen 40, including but not limited to adhesive, press-fit, orscrews.

Other features of needle assembly 30 may be formed by applying a coatingof material over cutter lumen 40. The coating of material may be appliedto cutter lumen 40 as a liquid, and then hardened to the necessaryrigidity for use in the human body after formation of the desiredfeatures thereon. In one version depicted in FIG. 9, the coating ofmaterial may be applied to cutter lumen 40 by injection molding. In thisversion, a mold 103 is designed such that the injected material may flowinto predetermined cavities and form the desired features over cutterlumen 40, including but not limited to vacuum lumen 52 and hub 76. Thegates (not pictured) through which the material is injected into themold may be located along the mold part line, shown as P_(L) in FIG. 9.Further, the gates may be located in the mold 103 underneath cutterlumen 40.

In this version, when the material is injected into the mold 103, it mayform an outer sheath 106 over cutter lumen 40, as well as taperedprofile 94 between piercing tip 86 and cutter lumen 40 (FIGS. 6, 7, 10,11). To assist in formation of tapered profile 94, piercing tip 86 mayinclude opening 100 (FIG. 4) through which the injected material mayflow. Flow of injected material through opening 100 from each side oftip 86 may strengthen attachment of the injected material to piercingtip 86.

The mold 103 may also be shaped so that the applied material forms hub76, flange 82, and vacuum manifold 84 over proximal portion 56 of cutterlumen 40. The mold 103 may also be designed so that hub 76 extends pastproximal end 62 of cutter lumen 40 in order to facilitate the mountingof needle assembly 30 to handle 20 or another suitable support.Alternatively, hub 76, including flange 82 and vacuum manifold 84 may beformed separately from the remainder of needle assembly 30 and beattached by gluing, press-fitting or any other suitable method known inthe art.

Referring to FIG. 9, prior to application of the coating of material, aslide 108 may be placed along exterior surface 60 of cutter lumen 40,substantially parallel to the longitudinal axis thereof. Moreparticularly, slide 108 may be placed on the underside of exteriorsurface 60. The material then coats cutter lumen 40 and slide 108,forming vacuum lumen 52 substantially parallel to the longitudinal axisof cutter lumen 40. Slide 108 also serves to prevent the appliedmaterial from blocking interlumen vacuum holes 70. The mold 103 may alsobe designed so that slide 108 may be placed in alternate locations inorder to orient vacuum lumen 52 above or to either side of cutter lumen40, so long as at least one interlumen vacuum hole 70 is present betweenvacuum lumen 52 and cutter lumen 40 to allow suction to be communicatedtherebetween.

While use of slide 108 is one process for forming vacuum lumen 52 in thecoating of material applied over cutter lumen 40, it is recognized thatother methods of forming vacuum lumen 52 in the coating of material arealso possible. For example, vacuum lumen 52 could be drilled out of thecoating of material after the material reaches sufficient hardness.

As shown in FIG. 10, in one version consistent with the invention, thecoating of material provides the combined cutter lumen 40 and vacuumlumen 52 with an egg-shaped frontal cross-section 110. During surgery,cross-section 110 promotes efficient motion of the needle assembly 30through tissue. However, it is recognized that the application of acoating of material to cutter lumen 40 may provide needle assembly 30with cross-sections of various shapes that are consistent with theprocess of the current invention. Further, as illustrated in FIGS. 9 and10, slide 108 may comprise a scoop-shaped cross-section 111 thatprovides vacuum lumen 52 with a generally scoop-shaped frontalcross-section 112. While this is helpful in providing the combinedcutter lumen 40 and vacuum lumen 52 with the egg-shaped frontalcross-section 110 described above, vacuum lumen 52 and slide 108 couldcomprise various frontal cross-sections that are consistent with theprocess of the current invention. For instance, slide 108 could have acircular frontal cross-section, thus providing vacuum lumen 52 with acircular frontal cross-section.

As shown in FIGS. 4 and 5, tab 98 on piercing tip 86 may be elongatedand slope downward in the proximal direction. In addition to serving asa point of attachment for welding piercing tip 86 to cutter lumen 40,tab 98 may also align and help hold slide 108 in place during molding.

Prior to application of the material to cutter lumen 40, a slide 112(FIG. 9) may be inserted into tissue-receiving port 42. Slide 112prevents any of the applied material from entering port 42.

Referring now to FIGS. 8 and 9, an axial slide 114 having a proximal end116 and a distal end 118 may be inserted into open proximal end 62 ofcutter lumen 40 prior to application of the coating of material. Axialslide 114 prevents the applied material from entering proximal end 62 ofcutter lumen 40. Further, axial slide 114 may be of a predeterminedlength such that distal end 118 extends into cutter lumen 40 distally oftissue-receiving port 42 but does not reach open distal end 64 of cutterlumen 40. Distal end 118 of slide 114 may further comprise anindentation 120. Piercing tip 86 may be attached to distal end 64 ofcutter lumen 40 in a manner that does not prevent material from flowinginto open distal end 64 during application of the material over cutterlumen 40. Accordingly, during the application process, material flowsinto open distal end 64 of cutter lumen 40 and into indentation 120 inaxial slide 114, thereby forming cutter stop 72 in cutter lumen 40distally of tissue-receiving port 42.

Additionally, in one version of the present invention, one or moreslides may be placed against exterior surface 60 of cutter lumen 40 inorder to hold cutter lumen 40 in position while the material is appliedover cutter lumen 40 and prevent deformation due to the pressure of theapplied material against exterior surface 60. As a result, outer sheath106 may include windows 122 (FIG. 3) through which cutter lumen 40 isexposed.

The injected material may be selected from materials including, but notlimited to, plastics, thermoplastics, thermoresins, and polymers. Forinstance, the molded features may be formed of a liquid crystal polymeror a glass reinforced polymer. One suitable material is a glassreinforced liquid crystal polymer such as VECTRA A130 available fromTicona Corp. In one version, the injected material may have a melt flowindex of at least about 10 grams/minute, more particularly at leastabout 15 grams/minute. Without being limited by theory, such a mold flowindex is thought to be beneficial for molding relatively long,thin-walled cross-sections.

While various versions of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch alternatives are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the present invention. Additionally,each component or element may be described in terms of a means forperforming the component's function. Accordingly, it is intended thatthe invention be limited only by the spirit and scope of the appendedclaims.

Me claim:
 1. A biopsy device, comprising: (a) a handpiece; (b) anelongated cannula, wherein the elongated cannula includes: (i) a closeddistal tip, the closed distal tip being configured to pierce tissue, and(ii) a transverse aperture formed proximal to the closed distal tip; (c)a tube extending distally from the handpiece, the tube being disposedwithin the elongated cannula, wherein the tube includes a firsttransverse aperture associated with the transverse aperture of theelongated cannula; and (d) a cutter slidably disposed in the tube, thecutter being operable to sever tissue protruding through the transverseaperture of the elongated cannula and through the first transverseaperture of the tube.
 2. The biopsy device of claim 1, wherein theclosed distal tip comprises a flat blade having two sharp edges, thesharp edges being coplanar with each other and converging at a sharppoint.
 3. The biopsy device of claim 2, wherein the distal tip furtherincludes a tapered profile region extending between the flat blade andthe exterior of the elongated cannula.
 4. The biopsy device of claim 1,wherein the transverse aperture of the elongated cannula and the firsttransverse aperture of the tube have substantially the same length. 5.The biopsy device of claim 1, where in the tube further includes aplurality of transverse apertures forming vacuum holes, wherein theplurality of transverse apertures forming vacuum holes are smaller thanthe first transverse aperture of the tube.
 6. The biopsy device of claim5, wherein the inner diameter of the elongated cannula is greater thanthe outer diameter of the tube, such that a lumen is defined between theinner diameter of the elongated cannula and the outer diameter of thetube.
 7. The biopsy device of claim 6, wherein the plurality oftransverse apertures forming vacuum holes are in fluid communicationwith the lumen.
 8. The biopsy device of claim 1, wherein the elongatedcannula is formed of a non-metallic material.
 9. The biopsy device ofclaim 8, wherein the tube is formed of a metallic material.
 10. Thebiopsy device of claim 1, wherein the closed distal tip is secured tothe tube.
 11. The biopsy device of claim 1, wherein the tube is fixedlysecured within the elongated cannula.
 12. The biopsy device of claim 1,wherein the elongated cannula has an interior transverse perimeter,wherein the tube has an exterior transverse perimeter, wherein theinterior transverse perimeter of the elongated cannula is greater thanthe exterior transverse perimeter of the tube such that the elongatedcannula fully encompasses the tube along a transverse dimension.
 13. Thebiopsy device of claim 1, wherein the elongated cannula is removablerelative to the handpiece.
 14. The biopsy device of claim 13, furthercomprising a hub providing a detachable connection between the elongatedcannula and the handpiece.
 15. The biopsy device of claim 14, whereinthe hub and the handpiece together provide a snap fit.
 16. The biopsydevice of claim 1, wherein the elongated cannula has a proximal end,wherein the tube has a proximal end, wherein the proximal end of thetube is proximal to the proximal end of the elongated cannula.
 17. Aneedle assembly for a biopsy device having a body wherein the needleassembly extends distally relative to the body, the needle assemblycomprising: (a) an outer cannula, the outer cannula having a distal endand a transverse aperture formed proximal to the distal end of the outercannula; (b) an inner cannula disposed within the outer cannula, whereinthe inner cannula has a distal end and a transverse aperture formedproximal to the distal end of the inner cannula, the transverse apertureof the inner cannula complementing the transverse aperture of the outercannula; (c) a distal tip secured relative to one or both of the innercannula or the outer cannula, the distal tip being configured to piercetissue; and (d) a cutter slidably disposed in the inner cannula, thecutter being configured to sever tissue protruding through thetransverse apertures.
 18. The needle assembly of claim 17, wherein thedistal tip is secured to the inner cannula.
 19. The needle assembly ofclaim 17, wherein the outer cannula is molded about the inner cannula.20. A needle assembly for a biopsy device having a body wherein theneedle assembly extends distally relative to the body, the needleassembly comprising: (a) an outer cannula, the outer cannula having adistal end and a transverse aperture formed proximal to the distal endof the outer cannula; (b) an inner cannula disposed within the outercannula, wherein the inner cannula has a distal end and a transverseaperture formed proximal to the distal end of the inner cannula, thetransverse aperture of the inner cannula complementing the transverseaperture of the outer cannula; (c) a distal tip configured to piercetissue; and (d) a hub configured to releasably secure at least part ofthe needle assembly relative to the body of the biopsy device.